Definition
TERPS is the FAA's official document of design criteria used to build instrument flight procedures in U.S. airspace, including instrument approaches, departures, and arrivals. It specifies the obstacle clearance, descent gradients, turn radii, and protected airspace dimensions that every published procedure must meet before it can be flown by aircraft operating under instrument flight rules.
Plain English
TERPS is the rulebook the FAA uses when designing the instrument procedures pilots fly, such as approaches into airports in low visibility. It sets the safety margins that keep aircraft clear of terrain and obstacles while flying these procedures.
Context Anchor
Seen when reading about how instrument approaches, departures, and other published instrument procedures are designed and approved.
Derivation
Terminal here means the area near an airport where aircraft transition between en route flight and landing. Instrument means the procedure is flown by reference to cockpit instruments rather than visual cues outside. Procedures refers to the specific, published step-by-step routes and altitudes. Together: the standard for designing the instrument-flown routes used near airports.
Why Pilots Care
Pilots depend on TERPS-compliant procedures to maintain safe obstacle clearance and navigation when flying by instruments in low visibility.
Analogy
TERPS is like a building code for instrument procedures. A pilot may not write the code, but the safety of the finished structure depends on the code being followed.
Intuition Check
Do not read “terminal” as the airport passenger building or as “final.” In TERPS, “terminal” means the airport-area environment where many instrument procedures begin, end, or connect.
Example Sentence 1
The new RNAV approach was designed to TERPS standards, so the published minimum altitudes already account for the surrounding terrain.
Example Sentence 2
Updates to TERPS can change minimum altitudes on published instrument procedures.